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            <h2 class="title" style="clear: both"><a id="dbset_feedback"></a>DB-&gt;set_feedback()</h2>
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      <pre class="programlisting">#include &lt;db.h&gt;

int
DB-&gt;set_feedback(DB *,
    void (*db_feedback_fcn)(DB *dbp, int opcode, int percent));  </pre>
      <p>
         Some operations performed by the Berkeley DB library can take non-trivial amounts of time.
         The <code class="methodname">DB-&gt;set_feedback()</code> method can be used by applications to
         monitor progress within these operations.  When an operation is likely to take a long time,
         Berkeley DB will call the specified callback function with progress information.
    </p>
      <p>
         It is up to the callback function to display this information in an
         appropriate manner.
    </p>
      <p>
         The <code class="methodname">DB-&gt;set_feedback()</code> method may be called at any time during the
         life of the application.
    </p>
      <p>
         The <code class="methodname">DB-&gt;set_feedback()</code> method returns a non-zero error value on
         failure and 0 on success.
    </p>
      <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;">
        <h3 class="title">Note</h3>
        <p>
                    Berkeley DB is not re-entrant. Callback functions should not attempt to make
                    library calls (for example, to release locks or close open handles). Re-entering
                    Berkeley DB is not guaranteed to work correctly, and the results are undefined.
            </p>
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              <h3 class="title"><a id="idm140711183276512"></a>Parameters</h3>
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                <h4 class="title"><a id="idm140711186771552"></a>db_feedback_fcn</h4>
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          <p>
                          The <span class="bold"><strong>db_feedback_fcn</strong></span> parameter is the
                          application-specified feedback function called to report Berkeley DB
                          operation progress.  The callback function must take three parameters:
                     </p>
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              <li>
                <p>
                                <code class="literal">dbp</code>
                            </p>
                <p>
                                The <span class="bold"><strong>dbp</strong></span> parameter is a reference to
                                the enclosing database.
                            </p>
              </li>
              <li>
                <p>
                                <code class="literal">opcode</code>
                            </p>
                <p>
                                The <span class="bold"><strong>opcode</strong></span> parameter is an operation
                                code.  The <span class="bold"><strong>opcode</strong></span> parameter may take
                                on any of the following values:
                            </p>
                <div class="itemizedlist">
                  <ul type="circle">
                    <li>
                      <p><a id="set_feedback_DB_UPGRADE"></a>
                                          <code class="literal">DB_UPGRADE</code>
                                    </p>
                      <p>
                                        The underlying database is being upgraded.
                                    </p>
                    </li>
                    <li>
                      <p><a id="set_feedback_DB_VERIFY"></a>
                                          <code class="literal">DB_VERIFY</code>
                                    </p>
                      <p>
                                        The underlying database is being verified.
                                    </p>
                    </li>
                  </ul>
                </div>
              </li>
              <li>
                <p>
                                <code class="literal">percent</code>
                            </p>
                <p>
                                The <span class="bold"><strong>percent</strong></span> parameter is the percent
                                of the operation that has been completed, specified as an integer
                                value between 0 and 100.
                            </p>
              </li>
            </ul>
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              <h3 class="title"><a id="idm140711187867936"></a>Class</h3>
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        <p>
                <a class="link" href="db.html" title="Chapter 2.  The DB Handle">DB</a>  
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              <h3 class="title"><a id="idm140711188217440"></a>See Also</h3>
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                     <a class="xref" href="db.html#dblist" title="Database and Related Methods">Database and Related Methods</a> 
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